WGM-enhanced liquid crystal microcavities for high-sensitivity acetylcholinesterase activity assay

In this study, we present a WGM-enhanced liquid crystal (LC) microcavity sensor for real-time, label-free, and high-sensitivity monitoring of acetylcholinesterase (AChE) activity and its inhibition. The 5CB molecules within the microcavity are anchored and adopt a radial configuration due to the influence of the amphiphilic myristoylcholine chloride (Myr). Hydrolysis of Myr by AChE induces a radial-to-bipolar transition in the LC microcavity, leading to changes in both optical textures and WGM resonances. The sensor integrates polarised optical microscopy (POM) for imaging LC molecular reorientation and greyscale quantification using ImageJ analysis, along with WGM spectral analysis. This combination demonstrates that WGM spectral monitoring offers superior sensitivity and accuracy in detection. The sensor achieves an AChE detection limit of 0.006 U/mL and enables the detection of fenobucarb and dimethoate at limits as low as 0.1 pg/mL and 1 pg/mL, respectively.